1. Field of the Invention
The present invention relates generally to a control system for an aerodynamic equipment, such as a wing, for aerodynamically providing vehicular driving stability at various vehicle driving conditions. More specifically, the invention relates to a control system for an aerodynamic equipment, which assists to provide higher cornering stability of the vehicle.
2. Description of the Background Art
Japanese Utility Model First (unexamined) Publication No. 61-101078 discloses a wing control system for an automotive vehicle. The shown system has a vertical wing which is mounted on the vehicular body for pivotal movement about a vertical axis. The control system is responsive to a vehicle speed higher than a predetermined speed and a steering angle greater than a predetermined angle, to cause angular displacement of the vertical wing for utilizing aerodynamic force exerted on the wing for stabilizing the vehicle.
Such prior proposed system is effective for providing stability of the vehicle at a vehicle speed higher than the predetermined speed and at a steering angle greater than a predetermined angle. However, as can be naturally understood, the prior proposed system does not cover overall vehicular driving range.
For example, the aerodynamic force to be generated by the vertical wing is proportional to square of the vehicle speed. Therefore, when the wing angle is set for providing optimal steering characteristics at high vehicle speed, the aerodynamic force to be induced by the vertical wing tends to increase understeer characteristics.
Therefore, it is an object of the present invention to provide a control system for an aerodynamic equipment of an automotive vehicle, which is effective for stabilizing vehicle at any vehicular driving condition.
In order to accomplish aforementioned and other objects, an aerodynamic system for an automotive vehicle, according to the present invention, employs an aerodynamic wing which is pivotable about a vertical axis. A control system is associated with the aerodynamic wing for controlling angular position thereof. The control system is responsive to a vehicle speed and a steering angle for deriving an angular position of the aerodynamic wing as a function of the vehicular speed and the steering angle in such a manner than the angular displacement of the aerodynamic wing from the neutral position is reduced according to increasing of the vehicular speed.
According to one aspect of the invention, an aerodynamics control system for an automotive vehicle comprises:
an aerodynamic wing mounted on a vehicle body, having a vertically extending wing surface and pivotable about a vertical axis within a predetermined angular range across a neutral position; PA1 a drive means for driving the aerodynamic wing for causing angular displacement about the vertical axis; PA1 a vehicle speed sensor for monitoring vehicle speed to produce a vehicle speed indicative signal; PA1 a steering angle sensor for monitoring steering angular position to produce a steering angle indicative signal; PA1 a control unit receiving the vehicle speed indicative signal and the steering angle indicative signal to derive a control signal for controlling driving magnitude of the drive means to place the aerodynamic wing at a desired angular position which is determined on the basis of the vehicular speed indicative signal and the steering angle indicative signal, the control unit deriving a rate of angular displacement of the aerodynamic wing relative to the steering angle indicative signal depending upon the vehicle speed indicative signal so that the rate is decreased according to increasing of the vehicle speed.
The control unit may derive the angular displacement from the neutral position on the basis of the vehicle speed and a steering angular displacement. In the alternative, the control unit derives the angular displacement of the aerodynamic wing from the neutral position with a predetermined primary lag factor. In the later case, it may be preferable that the primary large factor is variable depending upon the vehicle speed .